Crystal-facet-dependent catalysis of anatase TiO₂ on hydrogen storage of MgH₂

Various catalysts are developed to enhance the hydrogen storage performances of magnesium based hydride. In particular, the morphology of catalysts governs their surface energy and chemical interactions with Mg and hydrogen, which makes it possible to adjust the hydrogen reaction kinetics of MgH₂ through morphological design of the catalysts. Here, we report a novel crystal-facet-dependent catalysis of TiO₂ on hydrogen storage of MgH₂. Different facets dominant anatase TiO₂ (named TFx, x = 0, 10, 30, 50, 70 and 80) are prepared via a hydrothermal synthesis approach and then doped into MgH₂ via ball milling. Results show anatase TiO₂ with high percentage {001} facets has much better catalytic effect than that with low percentage {001} facets. The MgH₂-TF70 exhibits the best hydrogen sorption kinetics, showing apparent activation energy for dehydriding of only 76.1 ± 1.6 kJ mol⁻¹. The present study constructs a new bridge between the catalytic effect of catalysts with different crystal facets and the hydrogen storage property of MgH₂.